Two channels are welded at the tip of the flanges to form a box column. Properties of each channel  A = 5485 mm2 tw = 10 mm d = 250 mm bf = 100 mm tf = 15 mm Ix = 52 x 106 mm4 ly = 5 x 106 mm4 Distance from centroidal y-axis of the channel to the outer face of the web, x = 29 mm. Column height = 4 m. and effective length factor K = 1.0. both axes. The major x-axis of the channel is the x-axis of the built up column.   Calculate the axial compressive stress in the column due to a concentric load of 815 kN   What is the critical slenderness ratio of the built up column?

Two channels are welded at the tip of the flanges to form a box column.

Properties of each channel 

A = 5485 mm2

tw = 10 mm

d = 250 mm

bf = 100 mm

tf = 15 mm

Ix = 52 x 10⁶ mm4

ly = 5 x 106 mm4

Distance from centroidal y-axis of the channel to the outer face of the web, x = 29 mm. Column height = 4 m. and effective length factor K = 1.0. both axes. The major x-axis of the channel is the x-axis of the built up column.

Calculate the axial compressive stress in the column due to a concentric load of 815 kN

What is the critical slenderness ratio of the built up column?